Ante mortem diagnosis of amoebic encephalitis in a haematopoietic stem cell transplanted patient.

Acanthamoeba species are widely distributed free-living amoebae showing an increased role as human pathogens causing encephalitis, keratitis, pneumonitis and dermatitis. A haematopoietic stem cell transplanted (HSCT) patient developed purulent meningitis while awaiting regrafting. The meningitis was thought to be an endogenous infection arising from the mucous membranes primarily involving the cervicofacial regions, probably due to haematogenous spread facilitated by surgery. We diagnosed a fatal case of granulomatous amoebic encephalitis caused by Acanthamoeba castellanii by direct microscopy of a cerebrospinal fluid sample (CSF), Acanthamoeba cultivation, Giemsa staining, polymerase chain reaction and sequencing.